A protein-lipid complex, classified as a proteolipid was isolated from the Walker carcinosarcoma 256 (W256) and is designated as neoproteolipid-W (NPL-W). Systematic screening of animal and some human tumors revealed that some tumors have NPL-W, whereas other tumors (Sarcoma 180 and others) have a neoproteolipid which has different chromatographic properties. This type of neoproteolipid was designated as neoproteo-lipid-S(NPL-S). The presence of neoproteolipids was demonstrated also in blood sera of cancer patients and rats with W256 whereas sera from normal control human subjects and rats do not contain measurable quantities of these protein-lipid complexes. The general aim of this project is to study the biochemistry of these neoproteolipids and their practical implications for the detection of malignancy and/or efficacy of medical treatment of cancer. Lipid extracts from plasma/serum and blood cells will be investigated in cancer patients and normal subjects and in tumor-bearing animals and normal controls, hoping that the appearance (or alterations in the quantities) of neoproteolipids in blood will lead to a test for cancer. These studies will be made by using chromatographical and ultramicrochemical procedures. Both neoproteolipids will be isolated in pure form from lipid extracts of animal tumors by column chromatography. The chemical composition of NPL-W (continuation) and NPL-S (new endeavor) will be studied by using gas-liquid chromatography, liquid chromatography and microchemical procedures. The relationship between the alteration of glycosphingolipid patterns in tumors and formation of neoproteolipids will be investigated (NPL-W contains 70% glycosphingolipids). The presence of NPL-S in tissues other than malignant will be investigated to determine the degree of its tumor specificity (NPL-W is completed). Distribution of neoproteolipids in different subcellular organelles will be determined.